Spark plug



' 1,512,564 J. B. ROGERS SPARK PLUG fOct. 21 1924.

Filed July 25. 1921 l 4&4 A s ZWM w Patented ct. 2l, 1.924.

UNITED STATES nuns n. means, or cmcneo, ILLINOIS.

SPARK PLUG.

Application filed July 25, 1921.

-means are provided for preventing twisting the central conductor withinthe insulating core or body.

A further object of my invention is to provide an improved spark plugprovided with a metallicv sheath surrounding the insulating core, andwith a swivel ring bearing on this sheath to secure the plug in place.

A further object of my invention is to provide improved packing means atthe end of the central conductor which extends through the insulatingcore.

A further object of my invention is to provide an improved spark plughaving a metallic sheath surrounding the insulating core, with thismetallic sheath carrying one of the electrodes.

A urther object of my invention is to provide an improved spark plugwhich will be durable and eicient in operation, simple in constructionand cheap to manufacture. Further objects will appear from the detaileddescription to follow and from the ap ended claims.

the drawings in which two embodiments of my invention are shown- Figure1 is a central axial section through a spark plug;

F ig. 2 is a section on the line 2-2 of Fig. l

Fig. 3 is a section on the line 3-3 of Fig. 2

Fig. 4 is a detail perspective view of a split ring; V

Fig. 5 is a detail view showing the mounting of one of the electrodes,and

Fig. 6 is a view showing a modification.

Referring rst to F 1 to 5 inclusive, the spark plug shown thereincomprises an insulating ase or core 10, an electrode 11 mounted at theinner end of the core 10, a wiring terminal construction 12, mounted atthe outer end ofthe core 10, a conductor f 13, electrically connectingthe electrode 11 and the wiring terminal 12, `a metal sheath Serial No.487,327.

14 surroundingthe enlarged central portion of the core 10, an electrode15 carried by the sheath 14, a threaded ring or sleeve 16- which may bescrewed into the cylinder head to bring the electrodes 11 and 15 intothe desired position. Suitable packing washers 19 and 20'may be providedbetween the sheath 14 and the insulating core 10 to prevent the escapeof gas and to provide a cushion betweenthe metal and porcelain. Asuitable packing washer 21 may be provided between the sheath 14 and thebushing 18. These packing washers may be of any suitable material, andmay be of the type known as copper asbestos washers. Also, a suitablepacking washer 22 may be provided at the inner end lof the core 10,between the shoulder portion 23 0f the central conductor 13, and theshoulder portion' 24 on the pnrcelain core to prevent the escape of gasatt 's point and to provide a cushion between the metal and porcelain.

Inorder to relieve the central conductor 13 from any twisting strain,due to the screwing down or up of the binding screw 25, means 26 areiprovided at the upper end of the insulating core 10, to hold the centralconductor 13 against rotation inside of the core 10. This meanscomprises a washer member 27 having a central key-hole shaped opening28, through which the central conductor 13 eXtends,-the centralconductor 13 having a fiattened portion 29 at the point where it extendsthrough the washer, which flattened portion lies in the elongatedportion of the key-hole slot, so that relative rotation between theconductor and washer is prevented. Relative rotation between the washerand porcelain core 10 is prevented by means of downwardly extendingprojections 30 on the washer which fit into notches 31 (Fig. 3) in theporcelain core. Thus relative rotation is prevented between, the centralconductor 13 and the porcelain core 10. A sealing compound of cement maybe pro- .vided at the upper end of the insulating core 10, as indicatedat 32, to further effectually seal the connection between the centralconductor 13 and the porcelain core 10 at this point.

In assembling the central conductor 13 with respect to the porcelaincore 10, the central conductor carrying the electrode 11 tion 29 of thecentral conductor into the narrow portion of the key-hole slot toprevent relative rotation between the washer and conductor, rlhe washer27 is then titted to the core 10 so that the lugs 30 will enter thenotches 31, and the holding nut 34 is then screwed down to draw thecentral conductor 13 firmly into place. As the nut 34 is screwed down,the shoulder 23 of the central conductor is caused to be drawn snuglyagainst the packing washer 224 at the inner end oi the' core to elect atight connection at this point. Drawing down the nut 34 also forces thewasher 27 tirmly into place, and also compacts the cement at 32 (whichhas not yet hardened). The electrodes 11 and 15 may be of iridium,tungsten or other metals having a high melting point, spot-welded totheir supporting members. For this purpose, the electrode 11 is providedwith a shank` portion 35, which extends into a recess or socket in theend of the conductor 13. After the electrode is in place, it may bespot-welded or otherwise suitably secured. The electrode 15 is providedwith an enlarged portion 36 at its upper end (Figh) which lies in asuitable notch or recess 37 ,in the skirt portion of the sheath 14.After the electrode 15 has been placed in position with respect to thesheath 14, it may be secured in pla-ce by pressure and spot-welding, orin any suitable manner.

The swivel ring 16 may be held in place on the sheath 14 by means of asplit ring` 37, which can be sprung into place into an annular channelin the sheath. This split ring 37 keeps the swivel sleeve 16 in place onthe sheath 14e If desired, an anti-friction ring 38 may be' pro/videdbetween the shoulder 39 of the sheath 14 and the lower edge` of theswivel' sleeve 16.

It will be noted that both of the electrodes are mounted on the centralcore 10 so that the adjustment is not disturbed when the central core 1Gis removed from the bushing 17 for cleaning, etc. so that noreadjustment of the electrodes is necessary in reassembly.

It will also be noted that the constructionshown is in effect a completespark plug without the bushing 17, as the bushing 16 may be, if desired,screwed directly into the.

head of the cylinder as shown in Fig. 6. In Fig. 6 the construction maybe substantially the same as that shown in Fig. 1, except that thebushing 17 is omitted, and the swivel asiatica sleeve 16 is screweddirectly into the cylinder head 40, ln this construction, the cylinderhead is provided with a shoulder portion 41 against which the packingring 2]. bears, and is provided with an internally threaded portion 42,into which the swivel ring 16 screws.

It willl be seen that in both constructions is provided a plug which canbe connected and disconnected simply by screwing in or out the swivelring 1b, and in which it is not necessary to take the plug apart forcleaning, and in which there is no danger of any twisting strain beingexerted on that portion of the central conductor 18 which lies insidethe' porcelain core, und in which provision is made for preventing theescape of gas, and for cushioning the engagement between the metal partsand. the porcelain.

Having thus described my invention, what l claim as new and desire tosecure by Letters Patent of the United States is z- 1. A. spark plugconstruction comprising an insulating body, an electrode at one endthereof, a wiring terminal at the other cud thereof, a conductorextending axially through said insulating body, and electricallyconnecting said electrode and wiring terminal, said insulatin bodyhaving an enlarged portion, a meta sheath embracing and surrounding saidenlarged portion said metal sheath having two annular shoulders, onefacing outwardly7 and the other facin inwardly, a sleeve surrounding andswivelcd on said sheath and bearing on said outwardly facing shoulder, amember having an outwardly facing annular seat, an annular gasket onsaid seat, said member and sleeve being provided with intercngagingmeans whereby swiveling movement of said sleeve about said sheath willforce the sleeve inwardly, to force the inwardly facing shoulder on thesheath into sealing engage ment with said gasket; and to force thegasket into sealing engagement with the seat on said member. l

2. A spark plug construction comprisin an insulating body, an electrodeat one en thereof, a wiring terminal at the other end thereof, aconductor extending axially through said insulating bod and electricallyconnecting said electr e and wiring terminal, said insulating bodyhaving an enlarged portion, a metal sheath embracing and surroundingsaid enlarged portion, said metal sheath having two annular shoulders,one facing Ioutwardly and one facing inwardly, a sleeve surrounding andswiveled on said sheath and bearing on said outwardly facing shoulder,means on said sheath for holding said threaded sleeve against movementaway from said shoulder, a member having an annular outwardly facingseating shoulder, an annular gasket on said shoulder, said member andsleeve being provided with interenga. -ng means whereby swivelingmovement o said sleeve about said sheath will force the sleeve inwardly,to force the inwardly facing shoulder onthe sheath into sealing enagement with said gasket and to force sai gasket into sealing enga ementwith the outwardly facing shou der on said member.

3. A spark Ellg construction comprising an insulating an electrode atone end thereof, a, wiring terminal at the other end thereof, aconductor extending axially through said insulating body, andelectrically connecting said electrode and wiring terminal, saidinsulating body having an enlarged portion, a metal sheath embracing andsurrounding said enlarged portion, said metal sheath having twoannularshoulders,

one facing outwardlyyfand the other facing inwardl an electrofde carriedby said sheath or cooperation with said first electrode, a sleevesurrounding and swiveled on. said sheath and bearing on said outwardly7`facing shoulder, a member havin an outwardly facing annular seat, anannu ar gasket on said seat, Lsaid member and sleeve being provided withinterengaging means whereby Swiveling movement of said sleeve about saidsheath will force the sleeve inwardly, to force the inwardly facingshoulder on the sheath into sealing lengagement with said gasket, and toforce the gasket into sealing en agement with the seat on said member.

Witness whereof, I have hereunto subscribed my name.

JAMES B. ROGERS.

